<template>
  <div>
   
    <!-- <t-portal></t-portal> -->
    <div>
      c2 {{ a }}
    </div>
    <button @click="change">change</button>
  </div>
</template>

<script setup>

import { computed, onMounted, ref, nextTick,defineEmits ,defineProps} from 'vue';
onMounted(() => {

});
const props = defineProps(
  {
    a:String
  }
)
alert(props.a)
const emit = defineEmits(
  ['update:a']
)
const change = ()=>{
  alert(111)
  emit('update:a',7777777)
}
</script>

<style lang="scss" scoped>

</style>
